1. Field of the Invention
The present invention relates to a communication device, a communication method, and a computer readable recording medium for recording a program for executing the communication method.
2. Description of the Related Art
Conventionally, many research studies have been done on application of the information communication technology to fields where devices disposed in close vicinity to a human body are used, such as health and medical care. The institute of electrical and electronics engineers (IEEE) 802 LAN/MAN Standards Committee proposed the 802.15.6 standard protocol for the purpose of low-power local area wireless communication for Body Area Network (BAN) applications.
The IEEE 802.15.6 protocol defines a physical (PHY) layer and a medium access control (MAC) sublayer for the wireless BAN (also referred to as WBAN) operating in-body, on-body, or off-body. Here, the “body” is not limited to the human body and includes bodies of animals and organisms having propagation environment similar to the human body.
According to the IEEE 802.15.6 protocol, a device belonging to a BAN serves as a hub or a node. One hub and one or more nodes form an independent network. For example, the node is a small sensor such as a pulsimeter, an electrocardiograph, or an acceleration sensor which is attached to a user's body to monitor the user's physical condition and the hub is a terminal for collecting data from each sensor. Generally, a terminal serving as the hub has larger battery capacity than a sensor serving as the node because the terminal serving as the hub is not necessarily required to be directly attached to the user's body and should collect data from a plurality of sensors connected thereto. On the contrary, since the node is often powered by a small battery, it is important to reduce power consumed for communication in order to increase device operating time of the node.
Generally, a node waits for receiving a poll or data from a hub and performs transmission of data after receiving the poll or data from the hub in a given allocation slot in a bilink for bidirectional communication, as disclosed in PCT Publication No. WO2013/014757 published on Jan. 31, 2013.